Did I take this wrongly?

[Ben]

Tell me if I took this wrong...

My marina is dredging our entrance channel. The population is comprised of roughly 20% power, 80% sail craft. I have a trawler. I advised the dock-master of several variable depth readings I found 3 days ago between 4 foot and 8 foot. I recommended he should check real well before releasing the dredge operator from the work, because the channel seemed inconsistent.

And I was told:

Transducers are not an effective way to measure the depth of any channel. We have a surveyor that will certify the depth. I see you have a power boat, I doubt you will ever have an issue going anywhere.

I found that a might bit high-falutin', but nevertheless replied that I was contacting the Garmin Corporation to advise them their transducers are ineffective, and I would be removing my 3. What I did not include is that my Garmin 740s includes a log of my depth history with GPS coordinates.

I don't doubt that they will check the depths, but found his reply a bit condescending. Am I making mushroom clouds from mouse farts?

[swampu]

guy that is doing the dredging is probably a brother-n-law or something of the harbor master. Always something going on.

[randyt]

How did they dredge?
Randy

[N4712]

What's wrong with having a deeper marina? I would assume they would be dredging it with a backhoe not quite this big but similar.

[RT Firefly]

Greetings,
Mr. B. Just write it off to a dumb-ass dock master. Short of a lead line, the depth sounders in use today are the most effective way of determining depth IMO.

[psneeld]

From my experience with dredging small places...it's not uncommon for them to leave the bottom pretty ragged and eventually it settles out to a constant depth. I have been towing dredges in and out of small harbors for a decade now and it always seems the bottom is very ragged...usually not up to 4 feet...but lets say they want an 8 foot controlling depth...I would expect to see some 6's and a bunch of 10-12 depth readings so that everything settles out where they want it.

That's with a hydraulic dredge...not as familiar with bucket dredging.

[BoomerangIII]

Originally Posted by Ben

Am I making mushroom clouds from mouse farts?

Made me laugh...I'm stealing it. Regarding the reply you received..eh. You voiced your concern. Best you can do...

Reminds me of another sayin'
"Not my pig, not my farm"

[Moonstruck]

Ben, the harbor master must have been from up North. That is not the way we do it down South. We have just got to get our green head flies and no see'ems to working better. Yankees don't like them.

[Nomad Willy]

Ben I think they know well how deep the water is and the HM probably thought your comment was "condescending". He probably thought you were trying to tell him how to do his job and that you didn't approve of his performance.

Yup .. it's mouse farts.

[markpierce]

Let's leave it to the experts (?).

[BandB]

Originally Posted by Ben

Tell me if I took this wrong...

My marina is dredging our entrance channel. The population is comprised of roughly 20% power, 80% sail craft. I have a trawler. I advised the dock-master of several variable depth readings I found 3 days ago between 4 foot and 8 foot. I recommended he should check real well before releasing the dredge operator from the work, because the channel seemed inconsistent.

And I was told:

Transducers are not an effective way to measure the depth of any channel. We have a surveyor that will certify the depth. I see you have a power boat, I doubt you will ever have an issue going anywhere.

I found that a might bit high-falutin', but nevertheless replied that I was contacting the Garmin Corporation to advise them their transducers are ineffective, and I would be removing my 3. What I did not include is that my Garmin 740s includes a log of my depth history with GPS coordinates.

I don't doubt that they will check the depths, but found his reply a bit condescending. Am I making mushroom clouds from mouse farts?

There is a simple way of resolving the issue. Take a sink line or pole and go back through the same areas. Compare what you find to what you recorded and told him earlier. Then simply state that as you'd depended on your equipment you did decide to double check it, how you did, and that you confirmed your data was reasonably accurate. Tell him you have attached your latest findings and that you were simply concerned the marina was being misled and looking out for them.

[Richard W]

Maybe HM did not mind you "reporting", but did not like you "recommending".
Regardless, you reported, best you could do ... don't lose sleep over it.

[Ski in NC]

Twice I've hired dredgers to dig under my docks. Two of the most frustrating experiences in my life. Both bucket/barge types. One was a flat out thief, the other a crackhead. No wonder the OP's dockmaster was a bit testy.

And yes, bucket dredging leaves a mix of divits and hills. Depth sounder concentrates on the hills. So yes, a sounder is not a good way to assess. Also tend to be inaccurate in shallows. I used pvc pipe with a flange glued to end, dipped it to sound from a jon boat. Big high spots got just a regular pvc pipe as a flag. Dredger then supposed to go fix those spots. I ended up firing both before they got all the spots. As other's posted, humps tend to level out.

Just remembering those episodes has got me tweaked!!

[N4712]

In our pits we used a 100 dollar fish finder with the transducer mounted on a piece of angle iron. Then again this was for depths ranging from 50-60ft and hard limestone.

[cardude01]

Nice adverb! ;-)

[Sailor of Fortune]

It seems to me that the marina is the loser in this equation. Usually dredge jobs are surveyed by third party providers. Hills are then "knocked down" by various means to a consistent control depth, as agreed by the contract. Typically, several surveys before final monies are released. This process protects both parties.
Marina owner is a "chump" if he doesn't varify underwater work that he is paying for.

[High Wire]

Side scan from Humminbird or Lowrance shows the dredge cuts like there is no water. Well done dredge looks like large weld bead. I have the HB 798 HD SI unit and it shows prop scars in the mud. Plus it records to a SD chip so you can play it back on a laptop. Maybe someone in your area with SI could record a pass through. It takes about 2 minutes to record the whole channel. Any misses would be obvious.

[Ben]

Originally Posted by Richard W

Maybe HM did not mind you "reporting", but did not like you "recommending".
Regardless, you reported, best you could do ... don't lose sleep over it.

You're probably right. I intended to be helpful, but maybe it wasn't received in that spirit.

In retrospect, maybe I should call Garmin back and tell them not to remove all their transducers from the market...

[caltexflanc]

Well, he said he was going to have it surveyed. I'd guess he is more concerned about sail boaters complaining about it, which likely drove the project in the first place. Last thing he wants to put up with is more of that noise.

[Peter B]

Yeah…that was probably a bit of an over-reaction. Probably left them quite perplexed as to what particular bee got in your bonnet.